Never seen "Coupling", but Moffat's episodes for "Dr. Who" (which I've burned through in less than ten days) and the three episodes of "Jekyll" I've seen so far, are enough to show that the guy is a fantastic writer.

Too bad he's not planning on working in american television, because I'd really love to see more stuff from him.

I would argue that too much devotion to the source material was the biggest problem. The episodes that aired that were adapted from Moffat's scripts were godawful, for a number of reasons (29 minutes of carefully-constructed farce doesn't work when cut down to 22, the original scripts were written to the strengths of the Brit actors), while the one episode that aired that was a wholly original script (something about the expectations that come with picking up the dinner check) was not bad at all.

The one "Office" episode based directly on a British script was also pretty lousy; the difference is that the "Office" had time to stick around long enough to show that its original material was very funny.

I haven't had BBCA for all that long; isn't it unusual for a show, even a limited series like Jekyll, to show up within 2 months of the start of its run over there, and only a week after its end -- possibly "as soon as is allowed under contract", although I did indeed just make that up?